2011 Covert with RC4

I have a 2011 Covert with a DHX RC4. I want to upgrade my spring to a TI spring. I can't find one anywhere that has the same specs as my current spring. I am running a 500 x 2.35, I see TI in 2.30 and in 2.50
Could I switch to one of those, or do I need a 2.35? Any advice is greatly appreciated. Thanks